The structural characteristics, physical infrastructure, and social processes of a neighborhood increasingly are recognized as salient determinants of health. Although health conditions largely depend on individual behaviors, the place where people live may impact health outcomes over and beyond individual actions. Specifically we propose to investigate the extent to which the neighborhood context harms or promotes the health of its residents. The proposed study focuses on African American adults in Atlanta, Georgia, while comparing users and non-users, men and women, and younger and older persons. Drug use is defined as the use of cocaine, heroin and/or methamphetamine. The proposed study aims are: (1) to investigate the association between neighborhood context, individual characteristics and neighborhood perceptions with drug use;(2) among drug users, to examine the association between neighborhood context, individual characteristics, including situational use-related attributes, and neighborhood perceptions with the frequency of drug use;and (3) to identify the spatial patterns and to investigate neighborhood characteristics and individual-level characteristics associated with these spatial patterns. The guiding conceptual model builds on theories of neighborhood social and ecological organization, specifically social disorganization theory. This project comprises four distinct data sources, namely 1,600 individual interviews, data from the 2000 U.S. Census, Part 1 crime data and drug arrest data from the Atlanta Police Department which will be combined into an assessment of neighborhood structural characteristics, and systematic observations of neighborhood physical infrastructure and social processes. Census block groups will be used as proxy for neighborhoods. The study area will cover 100 census block groups and our pilot data show these to vary according to key structural characteristics. Our analytical approach will combine hierarchical linear modeling (HLM) and spatial "hot spot" analyses to explore the key hypotheses. The proposed study is significant because of its focus on African Americans, a population that is shown to be disproportionately impacted by illicit drug use and its social and health consequences, including HIV/AIDS. Its significance is enhanced by applying a multilevel, hierarchical approach that expands the focus from individual-level factors on drug use to the impact of neighborhood influences. In addition, the study has theoretical and research significance as its findings will provide useful information for policy-makers, urban designers, social and health service providers and the wider research community. Most importantly, the findings have the potential to make major contributions to future multi-level interventions targeting illicit drug use and its social and health consequences that are impacted by a mix of individual-level and neighborhood contextual factors. PUBLIC HEALTH RELEVANCE: This study proposes to investigate the neighborhood effects on drug use among African American adults over and beyond those at the individual level. Despite significant insights about individual-level characteristics found to influence drug use, our knowledge regarding contextual factors and their impact is limited. The findings from the study can have implications for many other health challenges including sexually transmitted infections, including HIV/AIDS, obesity, cancer, and cardiovascular disease.